Off-roading is a complicated thing, but it’s also quite simple. Yes, there are things like advanced traction control systems and complex dampers and fancy air intakes that affect off-road performance, but the main decider in how good a vehicle is off-road is something you can assess with just a simple glance. Which is why I’m confident when I tell you: The Tesla Cybertruck isn’t going to be “the best off-road vehicle.” But it will probably be a good off-road truck. Here’s what I mean.
The Cybertruck has the makings of a great off-road pickup truck, but it does not have the makings of the GOAT off-roader, no matter how much Tesla fans want it to be. And to be clear: The Cybertruck doesn’t have to outperform the Jeep Wrangler on the Rubicon to be an awesome truck. I think it’s going to end up being a lot of fun, and having seen one just yesterday on the roads of LA, I actually think it looks great.
But I’m here to bring some expectations back down to reality.
“Elon Explains Why the Cybertruck Is the Best Off-Road Vehicle” is the title of the YouTube video above showing Elon talking with Joe Rogan about independent suspension’s advantages over solid axles.
Listening to that, and seeing Rogan’s reaction reminded me a lot of the iPhone crowd explaining technology that Android users have had for years. “The new iPhone 8 is literally the best smartphone ever. It has wireless charging and optical image stabilization — it’s revolutionary!” you’d hear iPhone-ers say in late 2017, five years after the Nokia Lumia 920 Windows Phone debuted with both features and two years after the Samsung Galaxy S6 came out with both, as well.
It’s the same thing here; Musk is describing the most basic concept ever, here — the Cybertruck doesn’t have a diff that hangs down low because it has…wait for it…independent suspension. And oh, the ground clearance changes too?! How does it do that? Well, it has…wait for it…air suspension! Revolutionary!
I’m mostly just poking fun, because the truth is that iPhone users don’t know much about Android phones because they don’t care, and many Tesla owners don’t know much about off-road vehicles because they don’t care. And it’s fine; I applaud both Apple and Tesla for having created a customer-base that’s so devoted and focused. But let’s be real: Independent suspension with air springs is some seriously, seriously basic stuff. I mean, damn, look at this 2011 Jeep Grand Cherokee crush some off-road trails with air suspension:
Again, that’s 2011! A thirteen year-old car!
And here’s me off-roading a 2017 Land Rover Discovery with air springs and independent suspension:
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Behold the modern Land Rover Defender, which features independent suspension and air springs!:
And that reminds me, the real start of this whole air springs+independent suspension off-road movement was the debut of the 2002 Range Rover:
More importantly, we need to recognize that every electric off-road vehicle will have this same setup. For packaging, drivetrain efficiency, and unsprung-weight reasons, the solid axle — considered by many the ultimate off-road suspension for its toughness and articulation — is almost certainly going to die with the internal combustion engine. This means all vehicles will go to independent suspension. All of these off-roaders will also have to go to air suspension as well, because the ground clearance required for off-roading comes with far too big of a hit to overall vehicle drag (and thus range) — air suspension is the only way to have good clearance while off-roading and low drag on the street.
Three Things That Could Hold Back The Cybertruck. #1: Articulation
Anyway, now that we’ve established that the Cybertruck’s suspension setup is far from revolutionary (unless they have a trick up their sleeve that I’m not seeing), I can tell you a bit about why the truck is not going to be the very best off-road vehicle out there.
For one, while independent suspension does offer some ground clearance advantages over a solid axle, solid axle vehicles just drive over the tallest obstacles in their way; this lifts the diff on that axle high up off the ground, away from vulnerabilities. If you do hit your diff on something while rock-crawling, it’s not likely to break as Musk says in the clip, unless you’re driving very fast for such rocky off-road conditions. So the ground clearance advantage is real, but it’s not necessarily a humongous benefit off-road given typical off-road driving etiquette.
But the biggest drawback of an independent suspension setup is articulation. Look at the Rivian R1T pickup in the screenshot above; the vehicle is crawling over tough terrain, but because that suspension has so little travel — and because of the way independent suspension works re: roll center — one or more tires often lift off the ground. This not only means you have one less tire to propel the vehicle forward, but also that the ride becomes rather tippy, with the front end shooting into the air and then crashing down. What’s more, this puts lots more pressure on the traction control system to perform well so that torque gets sent to the wheels with grip. Let’s talk about that now.
Three Things That Could Hold Back The Cybertruck. #2: Traction
Go ahead and watch the Rivian R1T attempt to drive through a little V-notch in the mountainous terrain, and see how the nose finds itself jacked up in the air due to the vehicle’s lack of flex. With one fewer wheel on the ground to transfer torque to the road, the Rivian’s traction control system has to kick in, and as you can see in the clip above: It fails epically. The driver finds himself with his foot mashed hard on the accelerator pedal, and the truck just doesn’t move.
While I didn’t experience anything quite that egregious while off-roading the Rivian R1T, I did notice that the traction control system was reactionary, and made the vehicle feel a bit more flinchy and less relaxed as it tried to climb through difficult terrain.
Why? You might ask. Shouldn’t electric drivetrains be the ultimate in off-road propulsion given that they can vary output almost instantaneously (unlike an ICE)? It’s not that simple, as I wrote in my review of the Rivian R1T’s four-motor system:
To climb [a certain] grade at a given velocity (we’ll call it 2 MPH), [a] vehicle requires a certain amount of torque at the wheels. Imagine you’re driving a Jeep Wrangler Rubicon up this grade, and your foot is pressing the accelerator pedal a given amount, causing you to cruise up the grade at a constant velocity.
Now let’s say the passenger’s-side front wheel hits an ice patch and loses all grip, but the driver maintains the same pedal position. Will the tire slip (i.e. will its tangential speed exceed the vehicle speed)? The answer is: only if the three other tires — with which the tractionless tire is mechanically linked — cannot make up for the lost traction.
In other words, if the three tires with grip have enough traction such that the torque at the three wheels equals the required total wheel torque to ascend the grade, the vehicle will keep moving at a steady rate, and the tractionless tire’s tangential velocity at the tread will likely equal close to the vehicle’s velocity. The ascent will be smooth.
Put more simply, let’s just model the Jeep Wrangler Rubicon’s driveline as one big axle with four tires on it. Torque is being sent through that big axle, and all four tires are spinning at the same rate because they share a common shaft. If one or two or three tires roll over ice, the giant axle will continue moving steadily so long as the friction coefficient between the ground and the tire(s) with grip is capable of producing enough torque against the tire to meet or exceed the wheel torque needed to ascend the grade. (Note: There will be a yaw moment depending upon which tires have grip).
I go on:
With Rivian’s system, what happens? Well, let’s again say you’re climbing that same hill with the pedal depressed a certain amount. A given amount of current is being sent to the wheels, producing the requisite wheel torque to ascend the grade at 2 MPH.
Now let’s say the passenger’s side tire loses all grip; what happens? Well, the wheel torque there goes to zero, and the wheel slips until the vehicle can pull current from that motor [and clamp the brake]; does the wheel torque at the other three wheels instantly increase like it does with a fully-locked ICE in order to maintain a steady vehicle speed? Not instantly. The vehicle’s electronics have to quickly send more current to the other motors with grip to keep the vehicle moving at a given rate.
How much current do you send each wheel? What if you send too much current to a wheel that doesn’t have quite enough grip, causing wheel-spin? As for the wheel without grip; should it keep spinning at a rate that corresponds with vehicle speed so that it doesn’t have to accelerate once it does get grip? If so, how do you know what the vehicle speed is?
It’s really complicated.
The rest of that article includes a discussion with Rivian’s Principle Engineer of the drive system, Mason Verbridge. And he admits it’s really challenging trying to figure out what the vehicle reference speed is. How do you find how fast the ground is moving under the vehicle? If only one wheel is slipping, that’s easy enough, but if multiple are, then what? The traction control system has to predict the friction coefficient of the ground and the vehicle speed, and the reality is that often times the wheels will “flare up” a bit before the system can slow them down. This isn’t ideal for off-roading.
The analogies and comments I made about the R1T’s traction control system mostly apply to a four-motor system; I think the Cybertruck is expected to have two or three. Still, I mention all of this because of a recent Cybertruck off-road video, which was the impetus for this article.
The truck tries climbing some grades and struggles for traction in a situation where, clearly, a fully locked drivetrain like one you’d find in a Wrangler Rubicon would fare much better:
Three Things That Could Hold Back The Cybertruck. #3: Geometry
I mention in the lede of this article that off-road capability is something you can assess with just a quick glance at a vehicle, and that’s…somewhat true. Obviously, there are certain elements that have to exist for the vehicle to be good off-road — four-wheel drive, decent gearing, good tires, an OK traction control system etc. — but the most important element of a great off-road vehicle is favorable geometry: That means a compact overall size, low weight, and small overhangs. This is where the Cybertruck is going to be compromised, but not for any reason other than that: It’s a pickup truck. Pickup trucks just aren’t elite off-road vehicles.
There’s a reason that, throughout history, the very best off-road machines have been SUVs: the World War II Jeep, the Toyota FJ, the Land Rover Defender. They all combine solid axles with great geometry, which it’s hard to offer when you have a pickup bed that has to be at least five feet long. You’re either going to have to have that length in the wheelbase or in the rear overhang, and neither does you favors off road.
That’s the thing about off-road capability, especially rock crawling: Unlike racing, fancy electronic tricks aren’t going to save you. Off-roading is a simple game: get good torque to all the wheels, lock them together, and keep the overall dimensions and overhangs small — that’s how you win. There’s a reason why a Nissan GT-R can out-handle and out-accelerate any car from the 1940s, but when it comes to off-roading, one could make the argument that the World War II Jeep remains — even after almost 80 years — the best off-road platform of them all.
I say “platform” because the WWII Jeep could use a locker or two, but slap those in and it is in some ways more capable than any off-road vehicle available today. Just look at the video above! It has short overhangs, a small belly, good ground clearance that can be raised without making the vehicle too tippy or too tall due to the lack of a roof — it’s ideal, even today.
All that is to say: Off-roading requires one to adhere to certain fundamentals, and the Cybertruck, by virtue of being a modern electric truck, cannot. It’s going to be big because it’s a pickup truck. It’s going to be heavy because it’s electric and has to meet modern crash standards. Its articulation is likely going to be limited because it needs independent suspension for packaging space and driveline efficiency. Its traction control system isn’t necessarily going to be as good as a fully mechanically-locked system for the reasons I mentioned above (the video seems to imply that Tesla is still working on it).
I’m not saying the Cybertruck isn’t going to be great off-road. The Rivian R1T (which also features independent suspension, air springs that jack ride height way into the stratosphere, torquey electric motors, etc.) has fantastic approach, departure, and breakover angles for a pickup truck, which is why I consider it among the most capable of all trucks currently on the market.
I don’t know if the Cybertruck in TFL Off-Road’s video is at max ride height or is outfitted with the biggest tire package, but I can tell you that the wheelbase looks humongous, and that rear overhang doesn’t look ideal, either:
There’s no way to get around that. This falls into the “fundamentals” category. Yes, you can jack up the ride height via air suspension, but that’ll only go so far before CV angles become a problem. Even if you can jack up the ride height, think about how tall the vehicle now becomes. Getting it through tight trails might then become even more of a challenge.
Again, I’m not saying the Cybertruck won’t be great off-road, and overall I’m quite excited for its release. I believe it will be quite good, but all the Tesla fans who think it’s going to be the best off-roader out there, just look at the screenshot above and then look at this, and you’ll see that it doesn’t even pass the “glance” test:
I think I lost brain cells listening to that Musk-on-Rogan clip.
Rock crawling in an EV where all the batteries are on the bottom. Could that be a recipe for disaster? Or are the electrical bits protected?
Usually they are—I don’t know what the Cybertruck’s setup is going to be like, but it seems to be pretty standard to seal that sucker up on the bottom in beefy, beefy materials. Even on normal road vehicles, no one wants to start a crazy runaway battery fire by spinning out into a curb.
Troll level from Farley is at 11.
This is my supervisor behind the wheel! He got the call to go replicate the CT’s attempt in a Lightning.
https://x.com/jimfarley98/status/1724823063143784537?s=20
I’d be curious if you have any thoughts on this David, but my experience off roading is that more weight is generally not favorable. I’m probably not explaining physics of it right, but basically as you say torque application is needed up to the point that traction is lost in crawl situations and ideally the higher that slip threshold is the better you’re going to do in low traction situations. Increased weight requires more torque to move and thus the vehicle is more likely to overwhelm the tires-though I assume some of this is offset by greater weight pushing down on the contact patches.
Presumably some kind of bell curve of traction vs weight, but off roading once with a guy who brought a ford f350 diesel (by far heaviest vehicle I’ve first hand exp. off roading with) was that it just wallowed horribly in the deep snow and was damn near impossible to get unstuck compared to my friend’s Jeep Cherokee (fullsize version) in spite of having insane amounts of torque on tap. I have seen situations where soft trails start to crumble on the shoulders-and a heavier wider truck will be a liability here though again hard to tell where that line is, obvs modern Jeeps aren’t light by the standards of yesteryear. The CT is probably totally fine, even good by full size truck standards, and if he’d just left it at that nobody would care, but no he’s gotta claim it’s the best, smh.
Off road skills be damned, I saw one up near Ukiah, here in NorCal last weekend and it was so ugly I thought someone was driving a crashed F150 down the road. Then I saw the big RC or whatever it was on the front bumper and realized it was one of these awful things.
Or you could just say “Hold my Beer” like Ford… Slap an electric retractable moustache on the front bumper, throw a comically large battery between the frame rails, and call it a day.
A few thoughts…
I wonder how a CT would do against a Raptor over jumps at high speed! For some reason I keep thinking the CT would explode because of a lack of extensive battery padding.
While there’s a place for all styles (and I’m definitely not a fan of the CT style) I don’t feel that the CT is visually appealing with a backdrop of nature.
Lastly, a lack of GOAT capabilities aside, while I appreciate the innovative approach, the whole vehicle has, at least in my mind, a stigma attached to it. Not that one should care what people say or think, but I imagine people saying “oh you have a CT” and inquiring, then when you’re not there say “that thing is ugly, dude must be compensating for a lack of”. Heck, it’s subjective right? But a Raptor has balls! A Bronco or Wrangler have grit. A Tacoma had capabilities with practicality.
It’s sort of like a super fat hollow gold chain! Or even plated copper gold by the inch. The bling is 10X but it’s really just a somewhat capable show vehicle.
When the price for this is announced I’m pretty sure it will be more than a domestic crewcab with rebates plus a pretty nice built Jeep/Samurai or side by side or set of dirt bikes. And the domestic crewcab has a solid rear axle, so regardless of quoted tow weights it can tow durably and reliably for a long time. And the environmental impact of building a domestic crewcab is significantly lower.
But the CyberTruck owner will be able to be stuck in traffic smugly listening to Elon. Until they have to get a quote from a GM dealer to rebuild their rear suspension that has failed from carrying around the batteries.
I cant wait for the first post here about a Cybertruck getting stuck on Moab or something
DT’s greatest hits of off road clips and excellent explanations. Having gone wheeling in Colorado and Moab, I can say that some things cannot be faked.
As for controlling four wheel motors off-road: take a cue from CNC machines and control them like spindle motors. Rather than commanding torque, command a rotation speed and let the MOCON run the torque as necessary to achieve the commanded motor RPM. You would never do this on road (the driveability would be terrible), but it seems closer to the 4WD and Lockers ideal of engine-powered offroading.
Clever idea. I am not exactly sure how the differential in an electric motor powered axle is set up, but a physical locker would be nice. The danger might be the high torque of the motors snapping axle shafts though.
Fair point, but that’s something that can probably be handled by the MOCON as well. On most CNC machines, you can set alarm limits for spindle load; this would just be a soft limit rather than an alarm state.
You can also do some tricks like setting speed tolerance bands. This would allow for varying tire sizes and gentle turns without murdering the battery too much.
This is really interesting, I don’t know CNC, but it’s seemed to me that surely electric motors can be set up with controllers to give a level of granular throttle control and thus traction that isn’t possible with ICE motors and drivetrains-but as near as I can tell nobody is building them this way and still relying on more or less the same 4wd paradigm as ICE engined cars?
I don’t know exactly how EV motors are designed, but they’re probably similar to most spindle motors: 3 phase stator, wired either star or delta (or switchable, like my machines are) and a rotary encoder. With that architecture, we can coordinate spindle rotation with axis movement so precisely that we can hold a tap rigidly in the spindle and tap holes without needing springs to take up any errors. It seems like controlling wheels could be child’s play, as long as you don’t care about battery life!
Really, it’s probably the battery life that’s driving a lot of the decisions. Just imagine how much energy you would waste in a locked 4wd control regime (for a notional 4-motor system) by just turning on high-traction ground!
Very interesting, thanks for sharing that! And you’re probably right on battery life-though I would think an offroad only mode that consumed more energy for maximum traction makes a lot of sense short range sort of like how I’m not going to leave my ICE truck in low range or with lockers engaged for further than strictly necessary. Though realistically how far off road are any of these trucks really going-most probably see something rougher than poorly maintained fire road.
> Principle Engineer
Principal*
I can hear thousands of Tesla fans who’ve never offroaded anything in their lives screeching “ACKSHUALLY” and regurgitating Musk’s words as the absolute truth to refute this article.
“…having seen one just yesterday on the roads of LA, I actually think it looks great.”
A trip to the optometrist is in order David.
I refuse to watch the whole interview because I don’t hate myself THAT much, but the 40 second clip doesn’t have Elon claiming it will be the best offroad vehicle. He does the bit about breaking a diff, and he claims that the Cybertruck has “the best clear height of any vehicle” which is a bold but probably easy to disprove claim if BS. Also what the hell is with the text on that interview video? Is that what Tik Tok is all like?
This is such a stupid argument from Elon (what’s new about that?). The Cybertruck (I f’n hate that name) will never be as good as a small vehicle (Wrangler, Bronco, Tacoma). I don’t know that I’ve ever seen a vehicle stuck where the issue was the center diff or where an air suspension would allow an extra 2 feet of articulation. Having driven on Rubicon, Barrett Lake, and Fordyce Creek it is simply low air pressure, torque, and flexible suspension. We were on Rubicon when several test Jeep Rubicons were there prior to the initial launch. They were completely stock as the engineers wanted to see how they did on their namesake trail. All of us with our lifted leaf spring Jeeps were really impressed by how well a stock Rubicon did.
Some Tesla stan posted on Tweater glowing comments with a vid showing the CT going up a stair-stepped path in Hollister Hills Calif and then somebody added one of Grandma in her 20 yr old RAV4 doing the same path will much less drama.
Got a link?
Unfortunately not, it was about a week ago.
Meh… When I see Jeeps and other offroad vehicles go up and down gnarly trails, I usually think “I’d rather do that trail on foot or on my bicycle”.
On top of that, an increasing number of offroad trails are being closed to motorized vehicles often because of a minority of idiots.
You’d rather go up Hells Gate on a bicycle?
I know not every trail is Hells Gate or the like, but gnarly Jeep trails and fun walking/mountain biking trails are usually grossly different trails in grossly different areas. I really don’t understand what you mean.
Many time when driving a particularly pleasant trail I’ve thought “this is just car hiking.” The really gnarly offroading could maybe be better equated to climbing, as at the end of a really good wheeling/climbing you get a sense of accomplishment and get to compare the things you did well to the things you may have donked up. Also you could die, but that is only if you REALLY donk up…
I’m of the same opinion. I’ve been to Moab and rented a Jeep twice. With the exception of the easiest trails, I would have rather been out there in my running gear with a hydration backpack. It would have actually been quicker and I would have appreciated the views more. Mostly because I wouldn’t have been worried about rolling a Jeep off a cliff.
If I find myself back in Moab again, I’m going as a hiker/runner and not a Jeeper. There are more than enough foot trails out there to keep me away from the off road vehicles.
I can find a Jeep that’s already had some useful offroad mods, go pick that up for $7500 and leave the Remora* behind as soon as any trail gets a little challenging.
So. The whole point you make is borne out for easy money.
It might be pretty good as a truck, but with that pint-size bed I say it’ll be merely okay. It’s a big car with a trunk that you can leave open.
*because it sucks.
Around me $7,500 is a unmodified/poorly modified Samurai with no interior. But the actual negotiated transaction prices may be lower and people around me have too much money.
The lack of lockers in BEVs has an obvious solution from sewing machines and other setups that need to maintain a cadence regardless of workload. Stepper motors.
Wheel in midair? Wheel on ice? Wheel in mud? Stepper motor doesn’t care. As long as the torque required for Xrpm is available, that’s the speed it will go. And unlike a locker, a little programming will get it to vary wheelspeed to match the Ackerman angles and eliminate risk of damage.
Modern problems require old but not yet applied to vehicles solutions.
Except stepper motors don’t really work above a certain, not that fast, speed. To build a vehicle that can cruise 90mph but can also drive 1mph over a rock, it makes much more sense to use a different style of motor with a rotary encoder and a pretty serious motor controller.
You know, what they’re doing.
I think Frankencamry was looking for the control method, rather than the specific technology. I mentioned in another comment that while offroading, the vehicle’s motor controllers should be given speed commands, rather than torque commands. If the MOCONs are aiming for the same speed, they will output whatever torque is needed to maintain their speed. An added benefit is that a tolerance could be built in to allow a little speed deviation for uneven tire wear or gentle turns, or it could be locked all the way down for a hardcore “Lincoln Locker” (welded differential) effect.
So how long until we get a deluge of fight videos between Jeep Bros and Tesla Bros when the latter clog up trails and get stuck?
Not soon enough.
Since the Calvin peeing on Ford, Chevy, or Ram has questionable copyright implications, I suppose Cybertruck owners will have Elon peeing on the other brands.
My money is on Jeep Bros.
ElonBros aren’t really the tough outdoorsy thug types.
Oh dear, there’s already enough hate between Toyota Stans™️ and the Jeeple™️, and recently Bronco owners.
And I know none of those people are as attached to their car and the brand that made it as the members of the Church of Electric Jesus.
Star for “the Church of Electric Jesus”